Irmak MK et al. · 2002
Researchers investigated the influence of electromagnetic radiation from a digital GSM mobile telephone at 900 MHz on oxidant and antioxidant levels in rabbits. They measured adenosine deaminase, xanthine oxidase, catalase, myeloperoxidase, superoxide dismutase, glutathione peroxidase activities, nitric oxide, and malondialdehyde levels in sera and brains of exposed and sham-exposed rabbits. Serum SOD activity increased and serum NO levels decreased in exposed rabbits compared to sham-exposed rabbits, while other parameters did not change.
Testylier G, Tonduli L, Malabiau R, Debouzy JC · 2002
Rats were exposed to 2.45 GHz continuous wave at 2 or 4 mW/cm(2) for 1 h during the day, or to 800 MHz modulated at 32 Hz at 200 mW/cm(2) for 1 or 14 h during the night. Exposure at 4 mW/cm(2) caused a significant 40% decrease in mean acetylcholine release from hippocampus, maximal at 5 h post exposure. Fourteen-hour nighttime exposure at 800 MHz induced a significant 43% decrease in acetylcholine release during 11 p.m.-4 a.m. compared to control rats.
Paulraj R, Behari J · 2002
Researchers exposed 35-day-old Wistar rats to low-level continuous 2.45 GHz microwaves for 2 hr/day over 35 days at a power density of 0.34 mW/cm2 with a specific absorption rate of 0.1 W/kg. Exposed rats showed a significant increase in calcium ion efflux and ornithine decarboxylase activity and a significant decrease in calcium-dependent protein kinase activity in brain tissue. The authors suggested that the radiation affects membrane-bound enzymes linked to cell proliferation and differentiation, indicating a possible tumor-promoting role.
Lass L et al. · 2002
The study enrolled 100 subjects (37 female, 63 male) and randomly assigned them to an exposed group (10-20 min, 0.158 mW cm(-2)) or a sham-exposed group. The aim was to examine low-level 7 Hz-modulated 450 MHz radiation effects on human performance in visually presented neuropsychological tasks associated with attention and short-term memory. A battery of three different tests measured attention and short-term memory. The results of tasks 1 and 3 showed a significant increase in variances of errors (p<0.05) in the exposed versus the sham-exposed group. The results of task 2 indicated a significant decrease in errors (p<0.05) in the exposed group.
Finnie JW et al. · 2002
The study was designed to examine the effect of long-term exposure to global system for mobile communication (GSM) radiofrequency fields on vascular permeability in murine brains. Mice were given a 60-minute far-field, whole body exposure on each of 5 days per week for 104 weeks at specific absorption rates (SAR) of 0.25, 1.0,2.0 and 4.0 W/kg. In all exposed and control groups, albumin extravasation was minimal and was deemed insignificant.
Liu Y, Weng E, Zhang Y, Hong R. · 2002
Researchers exposed mice to a 50 Hz sinusoidal electromagnetic field at 0.2 mT or 6.0 mT for 2 weeks, and measured markers of the antioxidant system and cell membrane fluidity in brain and liver tissue. Malondialdehyde content in brain and liver increased with exposure, while total antioxidant capability decreased at both field strengths. When electromagnetic field exposure was combined with lead, the researchers observed synergic effects on lipid peroxidation.
Unknown authors · 2001
Researchers induced dopamine neuron damage in newborn rats by infusing 6-OHDA into the brain ventricles on postnatal day 3. At two months of age, the rats were exposed to a 10 Hz, 1.8–3.8 mT magnetic field for one hour daily over 14 days, while a sham-exposed group had the solenoid turned off. After exposure, magnetic-field-exposed rats with dopamine damage showed reduced irritability and oral activity when given a D1 receptor agonist and increased catalepsy when given a D1 receptor antagonist. The authors concluded that extremely low frequency magnetic fields reduce the reactivity of central dopamine D1 receptors.
Unknown authors · 2001
The study examined 30 human volunteers. Volunteers were exposed to a 28 microT circularly polarized 50 Hz magnetic field for 50 minutes in a double-blind crossover design. The majority of cognitive measures showed no significant effect of exposure. Verbal recall of a 15-word list after interference was significantly impaired during field exposure. Performance on a trail-making task requiring executive functioning also decreased with exposure.
Zook BC, Simmens SJ, · 2001
Researchers exposed Sprague-Dawley rats to 860 MHz pulsed or continuous radiofrequency radiation for 6 hours per day, 5 days per week from 2 up to 24 months of age. The specific absorption rate was 1.0 W/ kg averaged over the brain. The rats were offspring of females injected intravenously with 0, 2.5, or 10 mg/kg ethylnitrosourea to induce brain tumors. There was no statistically significant evidence that the radiation induced neoplasia in any tissues or promoted cranial or spinal nerve or spinal cord tumors. The radiation had no statistically significant effect on brain tumor number, volume, location, multiplicity, histological type, malignancy, or fatality.
Stagg RB et al. · 2001
Researchers exposed tube-restrained Fischer 344 rats to pulse-modulated 1.6 GHz Iridium cell phone fields at brain SARs of 0.16, 1.6 and 5 W/ kg for 2 hours. Core body temperature increased transiently by about 0.3 degrees C during the first 30 minutes of loose-tube restraint in conditioned animals. Immobilization alone caused a nearly 10-fold rise in ACTH and corticosterone in conditioned rats, and non-conditioned rats showed 3-10-fold higher hormone levels at 120 minutes. RF exposure did not change core body temperature, corticosterone, ACTH, or brain Odc, Fos, Jun mRNA compared with sham-exposed immobilized animals. The authors concluded that the pulse-modulated digital Iridium RF field at SARs up to 5 W/kg is incapable of altering these stress-related responses.
Johansen C, Boice JD, McLaughlin JK, Olsen JH, · 2001
A retrospective cohort study in Denmark included 420 095 cellular telephone users from 1982 through 1995. Cancer incidence was determined by linkage with the Danish Cancer Registry. Overall, 3391 cancers were observed with 3825 expected, yielding a significantly decreased standardized incidence ratio of 0.89. No excess risk was found for brain or nervous system tumors, salivary gland cancer, or leukemia. The results do not support an association between cellular telephone use and these cancers.
Inskip PD et al. · 2001
Researchers conducted a case-control study of intracranial tumors between 1994 and 1998. They enrolled 782 patients with glioma, meningioma, or acoustic neuroma and 799 controls. Cumulative use of more than 100 hours showed relative risks of 0.9 for glioma, 0.7 for meningioma, 1.4 for acoustic neuroma, and 1.0 for all tumors combined. No higher risks were seen for use of 60 or more minutes per day or regular use for five or more years. Tumors did not occur more often on the side of the head where the telephone was typically used.
Peyman A, Rezazadeh AA, Gabriel C · 2001
Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.
Lebedeva NN et al. · 2001
Hocking B · 2001
The paper describes early reports of microwave sickness from Eastern Europe and notes Western scepticism about them. It also considers recent reports by Western specialists and a possible neurological basis for the condition. The paper concludes that microwave sickness is a medical entity that should be recognized as a possible risk for radiofrequency radiation workers.
Hardell L, Hansson Mild K, Pahlson A, Hallquist A · 2001
Researchers conducted a case-control study of 233 patients aged 20-80 with histopathologically verified brain tumours, using two matched controls per case from the Swedish Population Register. Workers in the chemical industry had an odds ratio of 4.10 (95% CI 1.25-13.4) and laboratory workers an odds ratio of 3.21 (95% CI 1.16-8.85). Radiotherapy of the head and neck region gave an odds ratio of 3.61 (95% CI 0.65-19.9), medical diagnostic X-ray of the same area yielded an odds ratio of 1.64 (95% CI 1.04-2.58), and work as a physician gave an odds ratio of 6.00 (95% CI 0.62-57.7). Ipsilateral cellular telephone use increased the risk of tumours in the temporal, temporoparietal, and occipital areas with an odds ratio of 2.42 (95% CI 0.97-6.05).
Tattersall JE et al. · 2001
Finnie JW et al. · 2001
Researchers studied the effect of GSM radiofrequency fields on vascular permeability in the mouse brain using an exposure system operating at 898.4 MHz. Mice were given a single whole-body exposure for 60 minutes at a specific absorption rate of 4 W/kg, while control mice were sham-exposed or permitted free movement in a cage. No significant difference in albumin extravasation was detected between any of the groups.
Tsurita G, Nagawa H, Ueno S, Watanabe S, Taki M, · 2000
Male Sprague-Dawley rats were exposed to a 1439 MHz TDMA field. Exposure lasted one hour a day for two or four weeks. The study assessed blood-brain barrier permeability, cerebellar morphology, and body mass.
Sienkiewicz ZJ et al. · 2000
Muscat JE et al. · 2000
Researchers conducted a case-control study in five US academic medical centers between 1994 and 1998 using a structured questionnaire, enrolling 469 adults with primary brain cancer and 422 matched controls. The median monthly hours of use were 2.5 for cases and 2.2 for controls, and the multivariate odds ratio for regular use was 0.85 (95% CI, 0.6-1.2). No association was observed according to duration of use (P = .54), and cerebral tumors occurred more often on the same side as phone use (26 vs 15 cases; P = .06) while temporal lobe tumors showed the opposite pattern (9 vs 5 cases; P = .33).
Morgan RW et al. · 2000
Researchers conducted a large cohort mortality study among 195,775 Motorola employees from 1976 to 1996, classifying workers into high, moderate, low, and background radiofrequency exposure groups. Standardized mortality ratios for radiofrequency-exposed workers were 0.53 for brain cancers and 0.54 for lymphomas and leukemias. Internal rate ratios were near 1.0 for brain cancers and below 1.0 for lymphomas and leukemias, with no increased risk seen with longer exposure duration or latency. The findings were consistent across different exposure classifications and did not support an association between occupational radiofrequency exposure and these cancers.
Hietanen M, Kovala T, Hamalainen AM · 2000
Researchers analyzed EEG activity of 19 volunteers exposed to five different cellular phones operating at 900 MHz or 1800 MHz. Each subject completed six 30-minute experiments including one sham exposure, with real exposure lasting 20 minutes. Exposure to one phone caused a statistically significant change in absolute delta power, but relative delta power did not change and no effects were seen with other phones. The authors concluded that the observed difference was likely due to chance and that radiofrequency fields from cellular phones have no abnormal effects on EEG activity.
Bornhausen M, Scheingraber H · 2000
Wainwright P, · 2000
Researchers developed a finite element thermal model of the head to calculate temperature rises in the brain from cellular telephone radiation. The model used a 1 mm resolution MRI dataset segmented into ten tissue types and a finite element mesh generated with an automatic tetrahedral mesh generator. The model included natural metabolic heat production and power absorbed from the electromagnetic field, with SAR derived from a finite difference time domain model coupled to a model mobile phone. For publicly available equipment, the maximum temperature rise in the brain was about 0.1 °C. The steady-state temperature distribution was calculated using the Pennes bioheat equation.
